Just to follow up here --- I put this patch on hold for a few days
because I had to work on release notes. Now I'm glad I did, because
Robert Haas is pushing a proposal that would change the basis of
discussion:
https://www.postgresql.org/message-id/flat/CA%2BTgmoYSYmDA2GvanzPMci084n%2BmVucv0bJ0HPbs6uhmMN6HMg%40mail.gmail.com
If we do what he suggests there, then referencing "*VALUES*" in a
subquery with VALUES and ORDER BY would be broken anyway. In that
case I'd favor committing this patch as-is, to provide users with
a well-defined new behavior. So I think this should stay on hold
a bit longer to see what the outcome of that discussion is.
regards, tom lane